For example, as described in Patent Document 1, a tissue preparation for microscopic observation, e.g., pathological examination, is produced by the steps of: immersing a tissue preparation, which has been obtained from a human body, etc., in formalin so as to fix the tissue preparation; performing a dehydrating treatment, a degreasing treatment and a paraffin-penetration treatment; and embedding the tissue preparation, into which the paraffin has penetrated, (forming the tissue preparation into a block) in paraffin. Then, the tissue preparation embedded in the paraffin is sliced to form sliced pieces, and the sliced pieces are stained for microscopic observation.
In the above described steps for producing the tissue preparation, the paraffin-penetrated tissue preparation, in which the paraffin exists in the molten state, is embedded in paraffin.
Patent Document 1: Japanese Patent Kokai Gazette No. 2001-133371